The present invention relates to a luminous panel and to a building wall comprising such a luminous panel, especially as a structural element of the wall. In particular, the luminous panel may be employed as a cladding panel for an internal wall or a ceiling.
It is known to produce small luminaires using organic light-emitting diodes (OLEDs), which OLEDs are able to convert electrical energy into radiation. An OLED functional element comprises a stack of organic light-emitting layers inserted between two electrically conductive contacts forming front and back electrodes. An OLED functional element is conventionally encapsulated between two, front and back, protective substrates in order to form an OLED device. At least the front electrode of the OLED is transparent and likewise the protective first substrate, in order to allow the radiation emitted by the stack of light-emitting layers to exit through the front face of the OLED device. The transparent electrode may especially be based on a transparent conductive oxide (TCO) layer or on a transparent metal layer. The front and back protective substrates may especially be made of glass or of an organic polymer that is rigid or flexible. A flexible OLED device, in which the OLED is encapsulated between flexible polymer substrates rather than rigid substrates has the advantage of being thin, pliable and light.
An OLED device, whether rigid or flexible, may be associated, for example by adhesive bonding, with a support taking the form of a board so as to form a luminous board. The luminous board may be obtained by covering the support with a single OLED device or, when the size of the desired luminous area on the support exceeds the maximum available OLED device size, by covering the support with a plurality of juxtaposed OLED devices. Advantageously, the support used to form the luminous board is a structural element of a building wall, such as a cladding panel of an internal wall or a ceiling. It is then possible, by positioning a number of luminous boards on a conventional framework system of an internal wall or a ceiling, to obtain a large luminous wall capable of playing a double role as a wall and as a luminaire.
However, in such a luminous wall, there exists a visual discontinuity in each junction zone between two juxtaposed luminous boards, where systems for filling gaps between two cladding panels are conventionally placed. In the case where a luminous board is obtained by juxtaposing a plurality of OLED devices on one face of a support, there is also a visual discontinuity in each junction zone between two juxtaposed OLED devices on the support. These visual discontinuities take the form, in particular when the luminous wall is in the “on” state, of intermediate dark bands that do not emit light, which bands degrade the appearance of the luminous wall.